CVE-2026-87012 is a medium-severity (CVSS 4.3) CWE-754 vulnerability in open-webui. O3 Security confirms whether CVE-2026-87012 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Open WebUI: Any authenticated user can suppress calendar alerts instance-wide via a non-numeric alert value
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-87012.
Real-World Exposure
open-webuiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, backend/open_webui/models/calendar.py stored the calendar event meta.alert_minutes value without type validation and the shared upcoming-event scheduler compared that value numerically. An authenticated user with the calendar permission could store a non-numeric alert_minutes value that raised an exception and aborted the instance-wide alert pass, suppressing all users' reminders while the event remained in the lookahead window. This issue is fixed in version 0.11.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | open-webui | ≥ 0.9.0&&< 0.11.1 | 0.11.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for open-webui. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update open-webui to 0.11.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-87012 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-87012 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-87012. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-87012 in your dependencies?
O3 detects CVE-2026-87012 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.